Geokge edwin rigby



G. E. RIGBY.

SPRING FORK FOR MOTORCYCLES.

APPLICATION FILED MAY 26, I919.

Patent-ed Nov. 25, 1919.

GEORGE EDWIN ItIGBY, OF

MANCHESTER, ENGLAND.

SPRING-FORK ro'n MOTORCYCLES.

Specification of Letters Patent.

I Original application filed June 11, 1918, Serial No. 239,365. Divided and this application filed May 26, 1919.

Serial No.

To all whom it may concern Be it known that I, GEORGE EDWIN RIGBY, subject of the King of England, residing at Manchester, in the Kingdom of England, have invented new and useful Improvements Connected with. Spring-Forks for Motorcycles, of which the following is a. specification. 7

This invention relates to improvements in shock absorbing devices applicable to the spring forks at the front of motorcycles, one object being to provide a triangular fork, connected by parallel links to the opposite ends of the steering column and controlled by a laminated spring, with rigid projections, lugs, arms or side plates for holding the spring.

Further objects are to provide a centrally disposed attachment or housing integral with a crown or socket for the steering column and carrying, a pivoted bracket with adjusting means for holding a single centrally, situated spring; and to provide the arms or lugs of the fork with means, such as suspending links or a shackle for givmg a true or real hanging position to the eye of the laminated spring.

This application is pending application, June 11, 1918.

My invention will now be fully described with reference to the accompanying drawings, in which i i Figure 1 is a side elevation of the spring fork in connection with the steering head,

a division of my co- Serial 239,365, filed all provided with my improvements; Fig 2 is a side elevation, to a larger scale, of the attachment of the spring to the steering column; Fig. 3 is a side elevation of the bracket carrying the rear of the sprlng; Fig. 4 1s a part sectional front elevation of the means 7 for suspending the eye of the spring; Fig. 5

shows in front and side view the shackle for the spring.

' The triangular girder fork A, of which the main bars or rear members are in close proximity to the steering head B, has, according to my invention, at the inside of an integral upright lug, arm or C having an eye at its upper end to which is pivoted a depending shackle D. The-lower art of the shackle is dperforated to receive t "e eye of the laminate spring E. In this manner the upright rigid pro ections plate or side plates C enable the axis of suspension of the spring shackle D to be above the eye of the spring E so asto insure for the proper hanging action, while. at the same time the rigid plates C prevent tilting of the shackle under abnormal stresses of the-spring. The

shackle D can freely oscillate between the plates C.

This is exactly the reverse to theknown arrangement in which the axis of suspension of the spring is situated at the top of pivotal upright links which have their lower ends articulatedto the fork and so serve as tilting props for the latter.

The steering column end a crown consisting of a socket G brazed to the lower end of the steering column and the socket is coupled to the girder fork A F carries at its lower by two lower pivoted links H, one on either The laminations of the springE'are held together by the usual tie bolt e. The bracket I fits over the end E of the spring E and is made secure thereto by a bolt m. The bracket is hinged or pivoted at is to a housof a set screw cl and a locking bolt h, thereby providing for the adjustment of the spring mg G*' and is adjustable therein by means through; curved slots 0 in the housing G* into the bracket Z. Said slots 0 are concentric with the pivot is. 7

By first releasing the locking bolts h and then turning the set screw cl one way or the other, the tension of the spring E can be varied as will be easily understood. v The adoption of a crown and central housing in lieu of a cross-head enables a single central lateral spring to be used and thereby V obviates the lateral jolting due to the irregular action of the ordinary pair of springs.

The frame of the fork A comprises the usual rear braces, front lower and upper struts and middle stays, one on either side,

which extend from. about the center of the rear braces tothe said lugs which carry the plates whereto the shackle with the forward end of the laminated spring is pivoted. The

' difiere'nce: in construction existing between this girder fork and the known triangular girder fork resides moreparticularlyin the armor side and means for clamping the buttof-said provision of the forward three-way tubular lugs A having an integrator rigidly fixed described. T "I c'laim:

- Ina spring mountingfor motor cycles, the combination wlth a rigld housing, of ahead pivoted to rock therein, means for adjusting the head with'respect to the housing, a spring carried by the head and a 7 swingingshackle upon which the free end of the spring is lnnr :7 a I Ina springniounting for motor cycles, the combinationwlth a rigld'houslng, of a head'piv'oted to rock with respect to the housing means for adjusting the headwith respect to the housing, a laminated spring spring to the head.

I A structure as'recitedin claim 2, in combination with a shackle, the upper end of which is pivotally mounted and the lower end of which is pivotally connected with the outer end of the spring.

4. In" a fronufork mounting ii'or motor cycles, the combination with amain frame of a front fork pivotally connected thereto "for vertical movement with respect to'said frame, a steering post, a housing bracket plate, such as O for thepurpose f combination with aflixedito the steering post,,a head carried by said housing, a spring connected to the head,,a shackle pivotedat its upper end to apart of the "fork and to the lower end of which the -outer end of the spring is pivotally connected.

5.. A, structure as recited in claim 4c, ,in

means mounting the-head with respect to the hous ing, and means for adjusting said head upon its pivot and for holding it in adjusted position. 1

6. Afront fork mountingforimotor cycles for pivotally jcomprising in combination a mainframe member, a steerlng post, 'mounted to turn therein, a fork pivotally connected tothe steering post and having bodily turning movement therewith, but capable of "vertical movement withrespect thereto, a housing fixed to the turning post, a head pivoted in the housing for rocking movement, a

laminated spring, the butt of which is secured to said head, an ad usting element for moving the head with respect to the housing, and means for connecting the outer end of said spring to a portlon ofthe'fork.

7. A "structure as recited in claim 7, wherein the lastnamed connecting means comprises a shackle hung from a part of the fork andhaving' the outer end of the spring pivoted thereto. 7

- GEORGE EDWIN RIGBY'. 

